1 files changed, 211 insertions, 0 deletions
diff --git a/src/gui/platform/wasm/qlocalfileapi.cpp b/src/gui/platform/wasm/qlocalfileapi.cpp
new file mode 100644
index 0000000000..76b99361c4
--- /dev/null
+++ b/src/gui/platform/wasm/qlocalfileapi.cpp
@@ -0,0 +1,211 @@
+// Copyright (C) 2022 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#include "qlocalfileapi_p.h"
+#include <private/qstdweb_p.h>
+#include <QtCore/QRegularExpression>
+
+QT_BEGIN_NAMESPACE
+namespace LocalFileApi {
+namespace {
+std::string qtFilterListToFileInputAccept(const QStringList &filterList)
+{
+    QStringList transformed;
+    for (const auto &filter : filterList) {
+        const auto type = Type::fromQt(filter);
+        if (type && type->accept()) {
+            const auto &extensions = type->accept()->mimeType().extensions();
+            std::transform(extensions.begin(), extensions.end(), std::back_inserter(transformed),
+                           [](const Type::Accept::MimeType::Extension &extension) {
+                               return extension.value().toString();
+                           });
+        }
+    }
+    return transformed.join(QStringLiteral(",")).toStdString();
+}
+
+std::optional<emscripten::val> qtFilterListToTypes(const QStringList &filterList)
+{
+    using namespace qstdweb;
+    using namespace emscripten;
+    auto types = emscripten::val::array();
+
+    for (const auto &fileFilter : filterList) {
+        auto type = Type::fromQt(fileFilter);
+        if (type) {
+            auto jsType = emscripten::val::object();
+            jsType.set("description", type->description().toString().toStdString());
+            if (type->accept()) {
+                jsType.set("accept", ([&mimeType = type->accept()->mimeType()]() {
+                               val acceptDict = val::object();
+
+                               QList<emscripten::val> extensions;
+                               extensions.reserve(mimeType.extensions().size());
+                               std::transform(
+                                       mimeType.extensions().begin(), mimeType.extensions().end(),
+                                       std::back_inserter(extensions),
+                                       [](const Type::Accept::MimeType::Extension &extension) {
+                                           return val(extension.value().toString().toStdString());
+                                       });
+                               acceptDict.set("application/octet-stream",
+                                              emscripten::val::array(extensions.begin(),
+                                                                     extensions.end()));
+                               return acceptDict;
+                           })());
+            }
+            types.call<void>("push", std::move(jsType));
+        }
+    }
+
+    return types["length"].as<int>() == 0 ? std::optional<emscripten::val>() : types;
+}
+} // namespace
+
+Type::Type(QStringView description, std::optional<Accept> accept)
+    : m_description(description.trimmed()), m_accept(std::move(accept))
+{
+}
+
+Type::~Type() = default;
+
+std::optional<Type> Type::fromQt(QStringView type)
+{
+    using namespace emscripten;
+
+    // Accepts either a string in format:
+    // GROUP3
+    // or in this format:
+    // GROUP1 (GROUP2)
+    // Group 1 is treated as the description, whereas group 2 or 3 are treated as the filter list.
+    static QRegularExpression regex(
+            QString(QStringLiteral("(?:(?:([^(]*)\\(([^()]+)\\)[^)]*)|([^()]+))")));
+    const auto match = regex.matchView(type);
+
+    if (!match.hasMatch())
+        return std::nullopt;
+
+    constexpr size_t DescriptionIndex = 1;
+    constexpr size_t FilterListFromParensIndex = 2;
+    constexpr size_t PlainFilterListIndex = 3;
+
+    const auto description = match.hasCaptured(DescriptionIndex)
+            ? match.capturedView(DescriptionIndex)
+            : QStringView();
+    const auto filterList = match.capturedView(match.hasCaptured(FilterListFromParensIndex)
+                                                       ? FilterListFromParensIndex
+                                                       : PlainFilterListIndex);
+
+    auto accept = Type::Accept::fromQt(filterList);
+    if (!accept)
+        return std::nullopt;
+
+    return Type(description, std::move(*accept));
+}
+
+Type::Accept::Accept() = default;
+
+Type::Accept::~Accept() = default;
+
+std::optional<Type::Accept> Type::Accept::fromQt(QStringView qtRepresentation)
+{
+    Accept accept;
+
+    // Used for accepting multiple extension specifications on a filter list.
+    // The next group of non-empty characters.
+    static QRegularExpression internalRegex(QString(QStringLiteral("([^\\s]+)\\s*")));
+    int offset = 0;
+    auto internalMatch = internalRegex.matchView(qtRepresentation, offset);
+    MimeType mimeType;
+
+    while (internalMatch.hasMatch()) {
+        auto webExtension = MimeType::Extension::fromQt(internalMatch.capturedView(1));
+
+        if (!webExtension)
+            return std::nullopt;
+
+        mimeType.addExtension(*webExtension);
+
+        internalMatch = internalRegex.matchView(qtRepresentation, internalMatch.capturedEnd());
+    }
+
+    accept.setMimeType(mimeType);
+    return accept;
+}
+
+void Type::Accept::setMimeType(MimeType mimeType)
+{
+    m_mimeType = std::move(mimeType);
+}
+
+Type::Accept::MimeType::MimeType() = default;
+
+Type::Accept::MimeType::~MimeType() = default;
+
+void Type::Accept::MimeType::addExtension(Extension extension)
+{
+    m_extensions.push_back(std::move(extension));
+}
+
+Type::Accept::MimeType::Extension::Extension(QStringView extension) : m_value(extension) { }
+
+Type::Accept::MimeType::Extension::~Extension() = default;
+
+std::optional<Type::Accept::MimeType::Extension>
+Type::Accept::MimeType::Extension::fromQt(QStringView qtRepresentation)
+{
+    // Checks for a filter that matches everything:
+    // Any number of asterisks or any number of asterisks with a '.' between them.
+    // The web filter does not support wildcards.
+    static QRegularExpression qtAcceptAllRegex(
+            QRegularExpression::anchoredPattern(QString(QStringLiteral("[*]+|[*]+\\.[*]+"))));
+    if (qtAcceptAllRegex.matchView(qtRepresentation).hasMatch())
+        return std::nullopt;
+
+    // Checks for correctness. The web filter only allows filename extensions and does not filter
+    // the actual filenames, therefore we check whether the filter provided only filters for the
+    // extension.
+    static QRegularExpression qtFilenameMatcherRegex(
+            QRegularExpression::anchoredPattern(QString(QStringLiteral("(\\*?)(\\.[^*]+)"))));
+
+    auto extensionMatch = qtFilenameMatcherRegex.matchView(qtRepresentation);
+    if (extensionMatch.hasMatch())
+        return Extension(extensionMatch.capturedView(2));
+
+    // Mapping impossible.
+    return std::nullopt;
+}
+
+emscripten::val makeOpenFileOptions(const QStringList &filterList, bool acceptMultiple)
+{
+    auto options = emscripten::val::object();
+    if (auto typeList = qtFilterListToTypes(filterList); typeList) {
+        options.set("types", std::move(*typeList));
+        options.set("excludeAcceptAllOption", true);
+    }
+
+    options.set("multiple", acceptMultiple);
+
+    return options;
+}
+
+emscripten::val makeSaveFileOptions(const QStringList &filterList, const std::string& suggestedName)
+{
+    auto options = emscripten::val::object();
+
+    if (!suggestedName.empty())
+        options.set("suggestedName", emscripten::val(suggestedName));
+
+    if (auto typeList = qtFilterListToTypes(filterList))
+        options.set("types", emscripten::val(std::move(*typeList)));
+
+    return options;
+}
+
+std::string makeFileInputAccept(const QStringList &filterList)
+{
+    return qtFilterListToFileInputAccept(filterList);
+}
+
+} // namespace LocalFileApi
+
+QT_END_NAMESPACE